BrainFuck Language Interpreter

[Adikso]

BrainFuck Interpreter
Wait.. what is Brainfuck? - https://en.wikipedia.org/wiki/Brainfuck

Features:

• Works (but slow, Colobot limitation)
  
• Cell size customization (8bit default)
  
• Memory array size customization (1024 default)
  
• Pre-supply input from file
  

Code:

Code:

// Name: BrainFuck Interpreter (CBOT)
// Author: Adikso
// Created: 17.04.2016

extern void object::BrainFuck()
{
    
    file handle();
    handle.open("brainfuck.bf", "r");
    
    string script = "";
    while( not handle.eof()){
        script = script + handle.readln();
    }
    
    int script_size = strlen(script);
    
    interpret(script, script_size);
    
}

string getChar(int code){
    string table = "???????????????????????????????? !\"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~";
    string r = strmid(table, code, 1);
}

string getId(string character){
    string table = "???????????????????????????????? !\"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~";
    string r = strfind(table, character);
}

void interpret(string script, int lenght){

    // --------- SETTINGS ---------

    int cell_size = 8; // bit
    int memory_array_size = 1024;
    bool file_input = false;

    bool debugging = false;



    int cell_size_bound = pow(2, cell_size) - 1; // eg. 2^8 - 1 = 255
    message("BF Interpreter init..");

    // --------- DEBUGGER ---------
    file log();
    if(debugging){
        log.open("log.txt", "w");
        log.writeln("BF Interpreter init..");
    }

    // --------- FILE INPUT ---------
    file input();
    string file_input_content;
    int file_input_pos = 0;

    if(file_input){
        input.open("input.txt", "r");
        file_input_content = input.readln();
        input.close();
    }

    // --------- MEMORY INITIALIZATION ---------
    int memory[memory_array_size];
    
    // Hack
    for(int i = 0; i < memory_array_size; i++){
        memory[i] = 0;
    }

    
    int Ptr = 0;  // Pointer
    int IPtr = 0; // Position in file
    
    string output = "";
    
    while(true){
        
        if(IPtr >= lenght){
            break;
        }
        
        int charVal;
        string character = strmid(script,IPtr, 1);
        
        if(character == ">"){
            charVal = 1;
        }else if(character == "<"){
            charVal = 2;
        }else if(character == "+"){
            charVal = 3;
        }else if(character == "-"){
            charVal = 4;
        }else if(character == "."){
            charVal = 5;
        }else if(character == "["){
            charVal = 6;
        }else if(character == "]"){
            charVal = 7;
        }else if(character == ","){
            charVal = 8;
        }else{
            charVal = 0;
        }
        
        int val = memory[Ptr];
        
        switch(charVal){
            
            case 1: // >
                Ptr++;
                if(Ptr == memory_array_size) Ptr = 0;
                IPtr++;
                break;
            
            case 2: // <
                Ptr--;
                if(Ptr == -1) Ptr = memory_array_size - 1;
                IPtr++;
                break;
            
            case 3: // +
                if(val + 1 > cell_size_bound){
                    memory[Ptr] = 0;
                }else{
                    memory[Ptr] = val + 1;
                }
                
                IPtr++;
                break;
            
            case 4: // -
                if(val - 1 < 0){
                    memory[Ptr] = cell_size_bound;
                }else{
                    memory[Ptr] = val - 1;
                }
                IPtr++;
                break;
            
            case 5: // .
                output = output + getChar(val);
                IPtr++;
                break;
            
            case 6: // [
                if(val != 0){
                    IPtr++;
                    }else{
                        int depth = 0;
                        int i = IPtr + 1;
                        while(i < lenght){
                            string value = strmid(script, i, 1);
                            if(value == "["){
                                depth++;
                            }else if(value == "]"){
                                depth--;
                            }
                    
                            i++;
                    
                            if(depth == -1){
                                break;
                            }
                            
                        }
                
                        if(depth != -1){
                            message("missing pair ] at " + IPtr, DisplayError);
                            return;
                        }
                
                        IPtr = i;
                    }
                break;
            
            case 7: // ]
                {
                    int depth = 0;
                    int i = IPtr - 1;
                    while(i > 0){
                        string value = strmid(script, i, 1);
                        if(value == "["){
                            depth++;
                        }else if(value == "]"){
                            depth--;
                        }
                
                        i--;
                
                        if(depth == 1){
                            break;
                        }
                        
                    }
            
                    if(depth != 1){
                        message("missing pair [ at " + IPtr, DisplayError);
                        return;
                    }
            
                    IPtr = i+1;
                 }
                break;

            case 8: // ,
                if(file_input){
                    string character = strmid(file_input_content, file_input_pos, 1);
                    memory[Ptr] = getId(character);

                    file_input_pos++;
                }else{
                    message("File input is disabled. Aborting..", DisplayError);
                    return;
                }
                IPtr++;
                break;
            
            default:
                IPtr++;
            
        }

        if(debugging){
            string memoryStr = "";
            for(int i = 0; i < 30; i++) memoryStr = memoryStr + "|" + memory[i];

            log.writeln(IPtr+">"+memoryStr);
        }
        
    }
    
    message("Output: " + output);
    if(debugging){
        log.close();
    }
    
}

Usage:
You have to create "brainfuck.bf" file in colobot/files directory (eg. "~/.local/share/colobot/files" on Linux) with your brainfuck code.
You may want to create "input.txt" in the same directory if you want to use input from file.

Config:

Code:

// --------- SETTINGS ---------

int cell_size = 8; // Size of memory cell. 8bit => 255. It's the most common value.
int memory_array_size = 1024; // Size of memory array. Most common value in brainfuck is 30000.
bool file_input = false; // Gets input from input.txt

bool debugging = false; // Saves debug information to file

Examples:

Code:

++++[++++>---<]>.+[--->+<]>+++.---.+++.-------------.+++++++++++++.+++++.

Returns following output:

[tomaszkax86]

Pretty interesting usage of CBot. It's trivial but interesting. You could optimize it, for example you could turn repeating instructions (+++, ---, <<<, >>>) into a single instruction.

Also, since you have proven that CBot can simulate Brainfuck, and Brainfuck was already proven Turing complete, this means CBot is also Turing complete.

[PracticeBot13]

This Brainfuck thing, It scares me a little. I can only hope it doesn't destroy the world.

That said, I give you credit for an attempt at manipulating the Cbot language into loading another programming language. Reminds me of the Yo Dawg Meme:

[DavivaD]

++[---------->+<]>.-[++++>---<]>.-[---->+<]>++.+[----->+<]>.----.+++++.----------.-[--->+<]>-.--[->++++<]>-.-[->+++<]>-.--[--->+<]>--.+[---->+<]>+++.+[->+++<]>++.[--->+<]>+.--------.----.+++.-----------.+.-.[->+++<]>++.